Acceleration control system in electric vehicle

ABSTRACT

A control system includes an electric motor, an electric storage device, a throttle grip, a brake lever, a controller, and an acceleration/deceleration adjustment lever. The controller supplies electric power from the electric storage device to the electric motor in response to an acceleration command input by the throttle grip and causes the electric motor to drive the rear wheel. The controller adjusts the electric power generated by rotational power applied by the rear wheel in response to an acceleration/deceleration command from the acceleration/deceleration adjustment lever. The acceleration/deceleration adjustment lever is provided separately from throttle grip.

TECHNICAL FIELD

The present invention relates to an acceleration control system in anelectric vehicle in which an electric motor is supplied with electricpower corresponding to a command input by an acceleration operationmember and drives a drive wheel by output torque corresponding to theelectric power.

BACKGROUND ART

There is known an acceleration control system for adjusting outputtorque of an electric motor, in an electric vehicle which drives a drivewheel by the electric motor. In the acceleration control system, theoutput torque of the electric motor is adjusted in response to anoperation amount of an acceleration operation member such as a throttlegrip. As an example of the acceleration control system, there is acontroller disclosed in Patent Literature 1.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Laid-Open Patent Application    Publication No. 2008-229242.

SUMMARY OF INVENTION Technical Problem

Patent Literature 1 discloses that a throttle grip is rotated to providean acceleration command, and transmits the acceleration commandcorresponding to its angular displacement amount to a controller.However, a range in which the throttle grip can be rotated is limited toa degree to which it can be rotated by a driver's right hand, and is arelatively narrow range. Because of this, a change amount of the outputtorque with respect to a unit change amount of the angular displacementamount is great, and therefore it is difficult to finely adjust thechange amount of the output torque.

An object of the present invention is to provide an acceleration controlsystem in an electric vehicle which is capable of finely adjusting theoutput torque of the electric motor.

Solution to Problem

An acceleration control system in an electric vehicle of the presentinvention comprises an electric motor for driving a drive wheel byelectric power supplied to the electric motor; an acceleration operationmember for inputting a command for causing the drive wheel to beaccelerated; a controller for supplying to the electric motor electricpower corresponding to the command from the acceleration operationmember; and an acceleration amount adjustment member provided separatelyfrom the acceleration operation member; wherein the controller controlsan amount of the electric power supplied to the electric motor inresponse to the command from the acceleration adjustment member.

In accordance with the present invention, since the acceleration amountadjustment member which is different from the acceleration operationmember is provided, it becomes easy to finely adjust the output torquetransmitted from the electric motor to the drive wheel.

In the above invention, preferably, the controller generates theelectric power supplied to the electric motor in response to anoperation of the acceleration operation member, and suppresses theelectric power supplied to the electric motor in response to anoperation of the acceleration amount adjustment member.

In accordance with the above configuration, it becomes possible tosuppress the transmitted output torque by returning the accelerationoperation member to an initial state in which the acceleration operationmember is not operated. Also, by operating the acceleration amountadjustment member, in the state in which the acceleration operationmember has been operated, it becomes possible to suppress thetransmitted output torque. Thus, the output torque can be suppressed byusing either the acceleration operation member or the accelerationamount adjustment member.

In the above invention, preferably, the acceleration operation membermay be movable in a first predetermined direction from a predeterminedfirst reference position and is applied with a biasing force in adirection opposite to the first predetermined direction to return theacceleration operation member to the first reference position; theacceleration amount adjustment member may be movable in a secondpredetermined direction from a predetermined second reference positionand is applied with a biasing force in a direction opposite to thesecond predetermined direction to return the acceleration amountadjustment member to the second reference position; and the controllermay increase the electric power supplied to the electric motor as anoperation amount of the acceleration operation member with respect tothe first reference position increases and decreases the electric powersupplied to the electric motor as the acceleration operation membermoves closer to the first reference position when the accelerationoperation member returns to the first reference position; and thecontroller may decrease the electric power supplied to the electricmotor as an operation amount of the acceleration amount adjustmentmember with respect to the second reference position increases andincreases the electric power supplied to the electric motor as theacceleration amount adjustment member moves closer to the secondreference position when the acceleration amount adjustment memberreturns to the second reference position.

In accordance with the above configuration, when the accelerationoperation member is moved in the first predetermined direction, thedrive wheel is accelerated, while when the acceleration operation memberis returned to the first reference position, acceleration of the drivewheel stops. When the acceleration amount adjustment member is moved inthe second predetermined direction, a degree of the acceleration of thedrive wheel is mitigated, while when the acceleration operation memberis returned toward the second reference position, the degree of theacceleration of the drive wheel is increased. By moving the accelerationamount adjustment member different from the acceleration operationmember in the second predetermined direction or returning it to thesecond reference direction as described above, an acceleration amountcan be adjusted, which improves flexibility of the operation.

In the above invention, preferably, the controller nullifies theoperation of the acceleration operation member and halts electric powersupply to the electric motor, when the acceleration amount adjustmentmember is moved by a predetermined operation amount or greater in thesecond predetermined direction from the second reference position.

In accordance with the above configuration, by operating theacceleration amount adjustment member, it becomes possible to preventthe drive wheel from moving, even when the acceleration operation memberis operated by the driver or a third party.

In the above invention, preferably, the electric vehicle comprises asteering device including two gripping members which are gripped bydriver's right and left hands, respectively; the acceleration operationmember is provided at one of the gripping members; and the accelerationamount adjustment member is provided at the other gripping member.

In accordance with the above configuration, the acceleration operationmember and the acceleration amount adjustment member can be operatedwith different hands, respectively. Thus, the acceleration amount can beadjusted with right and left hands.

In the above invention, preferably, the acceleration operation member isan operation member of a throttle grip shape which is attached on theone of the gripping members such that the acceleration operation memberis operated to be rotatable in the first predetermined direction aroundan axis of the acceleration operation member; and the accelerationamount adjustment member is an operation member of a lever shape whichis operated to be movable in the second predetermined direction.

In the above invention, preferably, the controller may supply to theelectric motor prescribed electric power corresponding to the operationamount of the acceleration operation member; when the accelerationamount adjustment member is moved by the predetermined operation amountor more and the acceleration operation member is operated, beforestarting of the electric vehicle, and then the acceleration amountadjustment member is returned by a predetermined operation amount ormore to activate the electric motor to start the electric motorcycle,the controller gradually increases the electric power supplied to theelectric motor to the prescribed electric power.

In accordance with the above configuration, it becomes possible toprevent a situation in which driving power increases rapidly in responseto the operation amount of the acceleration operation member and hencethe electric vehicle starts abruptly, during starting.

In accordance with the above configuration, since the accelerationoperation member is the operation member of the throttle grip shapewhich is operated to be rotatable, its rotational angle can be easilykept at a constant value, and hence the operation amount is kept easily.By comparison, since the acceleration amount adjustment member is theoperation member of the lever shape, it can be moved to a great degreein a short time, and the electric vehicle can be decelerated quickly bythe acceleration amount adjustment member.

In the above invention, preferably, when a predetermined torqueincreasing condition is satisfied after the acceleration amountadjustment member has been moved in the second predetermined direction,the controller supplies to the electric motor instantaneous electricpower which is greater than prescribed electric power corresponding toan operation amount of the acceleration operation member at a time pointwhen the predetermined torque increasing condition is satisfied.

In accordance with the above configuration, the output torque can beincreased rapidly after the output torque is decreased by the operationof the acceleration amount adjustment member.

Advantageous Effects of Invention

In accordance with the above configuration, the output torque of theelectric motor can be finely adjusted.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a right side view of an electric motorcycle as an example ofan electric vehicle including one of control systems according toEmbodiment 1 to Embodiment 4 of the present invention.

FIG. 2 is a block diagram showing an electric configuration of thecontrol system in each of electric motorcycles according to Embodiment 1to Embodiment 3 of the present invention.

FIG. 3 is an enlarged plan view showing a region near a handle of theelectric motorcycle according to Embodiment 1 of the present embodiment.

FIG. 4 is a flowchart showing a procedure of an electric motor controlprocess in the electric motorcycle of FIG. 1.

FIG. 5A-C are graphs showing an example of a change in an operationamount of an accelerator grip, a change in an operation amount of anadjustment lever, and a change in torque, which changes occur with time,when a torque adjustment process is executed.

FIGS. 6A and 6B are graphs showing an example of a change in theoperation amount of the accelerator grip, a change in the operationamount of the adjustment lever, and a change in the torque, whichchanges occur with time, when a regenerative braking force adjustmentprocess is executed.

FIG. 7 is a flowchart showing a procedure of a starting process of theelectric motorcycle of FIG. 1.

FIG. 8A-B are graphs showing an example of a change in the operationamount of the accelerator grip, a change in the operation amount of theadjustment lever, and a change in the torque, which changes occur withtime, in the electric motorcycle of FIG. 1.

FIG. 9A-B are graphs showing an example of a change in the operationamount of the accelerator grip, a change in the operation amount of theadjustment lever, and a change in the torque, which changes occur withtime, in the electric motorcycle of FIG. 1.

FIG. 10A-B are graphs showing a change in the accelerator grip, a changein the torque, and a change in the adjustment lever, which changes occurwith time, in the electric motorcycle of FIG. 1.

FIG. 11 is an enlarged plan view showing a region near a handle of anelectric motorcycle according to Embodiment 2 of the present embodiment.

FIG. 12 is a block diagram showing an electric configuration of acontrol system in an electric motorcycle according to Embodiment 4 ofthe present invention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the drawings. Hereinafter, electric motorcycles 1, 1A to 1Cwill be described as the embodiments of an electric vehicle of thepresent invention. The stated directions are from the perspective of thedriver which straddles the electric motorcycles 1, 1A to 1C. Throughoutthe drawings, the same or corresponding components are identified by thesame reference numerals, and repetitive description of them will not begiven. The present invention is not limited to the embodiments andaddition, deletion, and change can be made without departing a spirit ofthe invention.

Embodiment 1

As shown in FIG. 1, an electric motorcycle 1 includes a front wheel 2and a rear wheel 3. The front wheel 2 is rotatably mounted to a lowerend portion of a front fork 4. The front fork 4 is coupled to a bar-typehandle 5 via a steering shaft (not shown). The steering shaft isrotatably supported by a head pipe 7. A main frame 8 is mounted to thehead pipe 7. The main frame 8 extends rearward and downward from thehead pipe 7 and is positioned to extend along a center line in a vehiclewidth direction when viewed from above. The head pipe 7 is provided witha pair of down frames 9. The pair of down frames 9 extend downward whileprotruding outward in the vehicle width direction, from the head pipe 7,are bent, and then extend rearward.

A pivot frame 10 is provided at a rear lower end portion of the mainframe 8 and rear end portions of the pair of down frames 9. The rearlower end portion is coupled to the rear end portion via the pivot frame10. The pivot frame 10 is provided with a swing arm 11. A front endportion of the swing arm 11 is coupled to the pivot frame 10 such thatthe swing arm 11 is pivotable around the front end portion. The rearwheel 3 is rotatably mounted to a rear end portion of the swing arm 11.A rear wheel suspension 13 is mounted to the front end portion of theswing arm 11. The rear wheel suspension 13 is coupled to the rear endportion of the main frame 8. The rear wheel suspension 13 is mounted toand between the swing arm 11 and the main frame 8. A seat rail 12 isprovided at the rear end portion of the main frame 8. The seat rail 12extends rearward and upward from a rear portion of the main frame 8. Adriver straddle seat 14 is mounted over the seat rail 12. In front ofthe seat 14, a dummy tank 15 is disposed. The dummy tank 15 ispositioned between the seat 14 and the handle 5.

A controller 16 is accommodated into the dummy tank 15. An electricmotor case 17 is provided under the dummy tank 15. The electric motorcase 17 is mounted to the main frame 8 and the pair of down frames 9. Anelectric motor 18 is accommodated into the electric motor case 17. Theelectric motor 18 is, so-called three-phase AC motor, and is coupled tothe rear wheel 3 which is a drive wheel, via a power transmissionmechanism 19. The power transmission mechanism 19 includes, for example,a chain, a belt, or a drive shaft. The power transmission mechanism 19is configured to transmit output torque of the electric motor 18 to therear wheel 3 which is the drive wheel, and transmit a rotational powerof the rear wheel 3 to the electric motor 18. The electric motor 18generates electric power by the rotational power transmitted from therear wheel 3. As shown in FIG. 2, the electric motor 18 thus configuredis coupled to an electric storage device 20 via an inverter device 21.

The electric storage device 20 and the inverter device 21 are positionedbetween bent portions of the pair of down frames 9. The electric storagedevice 20 is able to charge and discharge DC power. The inverter device21 has an inverter function which converts the DC power discharged fromthe electric storage device 20 into three-phase AC power and suppliesthe three-phase AC power to the electric motor 18, and a converterfunction which converts the AC power generated in the electric motor 18into the DC power and stores the DC power in the electric storage device20. The inverter device 21 is coupled to the controller 16.

The controller 16 has an inverter driving section 22. The inverterdriving section 22 controls driving of the inverter device 21, to bespecific, performs PWM control such that the AC power supplied to theelectric motor 18 is adjusted by adjusting a frequency and voltage ofthe AC power supplied to the electric motor 18 and the electric powergenerated in the electric motor 18 is generated by changing a dutyratio. For example, the duty ratio is adjusted and the generatedelectric power is changed by changing a switching cycle and a timing ofa switching element of the inverter device 21 based on a vehicle speed.

The controller 16 includes a determiner section 23. The determinersection 23 receives commands input by operation members attached on theelectric motorcycle 1 via sensors, and determines whether or notconditions are satisfied based on the received commands. The controller16 and these operation members construct a control system 33.Hereinafter, the operation members attached on the electric motorcycle 1will be described with reference to FIGS. 2 and 3.

As shown in FIG. 3, a handle 5 which is a steering device has a pair ofright and left grips 5 a and 5 b. As shown in FIG. 2, the pair of grips5 a and 5 b which are gripping members are provided at a right endportion and a left end portion of the handle 5, respectively. The rightgrip 5 a is an accelerator grip by which an acceleration command (to bespecific, torque command) for acceleratively rotating the rear wheel 3is input. The accelerator grip 5 a which is an acceleration operationmember is rotatable around an axis L1 along which the handle 5 extends,and is positioned in a grip reference position (first referenceposition) in a non-operated state. The accelerator grip 5 a is appliedwith a biasing force for biasing the accelerator grip 5 a in apredetermined direction (i.e., direction away from the driver, adirection opposite to a direction indicated by an arrow A, i.e.,forward) toward the grip preference position. The accelerator grip 5 ais rotatable in a direction (i.e., direction toward the driver, thedirection indicated by the arrow A, rearward) opposite to thepredetermined direction against the biasing force.

The accelerator grip 5 a is provided with an accelerator grip sensor 24.The accelerator grip sensor 24 outputs an acceleration commandcorresponding to an angular displacement amount (hereinafter simplyreferred to as “operation amount.”) θ from the grip reference position.To be specific, the acceleration command increases output torque T withan increase in the angular displacement position. The accelerator gripsensor 24 is coupled to the controller 16 and provides the accelerationcommand to the controller 16. The inverter driving section 22 in thecontroller 16 controls driving of the inverter device 21 in response tothe acceleration command to adjust the electric power supplied to theelectric motor 18. To be more specific, the controller 16 increases theoutput torque of the electric motor 18 in response to the rotation ofthe accelerator grip 5 a from the grip reference position toward thedriver and decreases the output torque of the electric motor 18 inresponse to returning of the accelerator grip 5 a to the grip referenceposition.

A brake lever 25 is provided in front of the accelerator grip 5 a. Thebrake lever 25 can be gripped together with the right grip 5 a in astate in which the brake lever 25 is grabbed with fingers of thedriver's right hand. By pulling the brake lever 25 toward the driverwith the fingers of the driver's right hand grabbing the brake lever 25,the brake lever 25 is pivotable toward the driver (two-dotted line inFIG. 3) from the brake lever reference position (see solid line in FIG.3). The brake lever 25 is applied with a biasing force for returning thebrake lever 25 to the brake lever reference position. When the drivertakes off with the brake lever 25 in a state in which the brake lever 25is pulled toward the driver, the brake lever 25 returns to the brakelever reference position.

The brake lever 25 is an operation member for activating a front wheelbrake mechanism (not shown) provided for the front wheel 2. By pullingthe brake lever 25 toward the driver, the front wheel brake mechanism isactivated, to apply a mechanical brake force to the front wheel 2. Byadjusting a displacement amount of the brake lever 25, the braking forceapplied to the front wheel 2 can be adjusted. The brake lever 25 havingsuch a function is provided with a brake sensor 26. The brake sensor 26is a switching sensor and is configured to detect whether or not thebrake lever 25 has been operated. The brake sensor 26 is coupled to thecontroller 16 and provides a result of detection to the controller 16.

By comparison, an adjustment lever 27 is provided in front of the leftgrip 5 b. The adjustment lever 27 can be gripped together with the leftgrip 5 b in a state in which the adjustment lever 27 is grabbed withfingers of the driver's left hand. By pulling the adjustment lever 27toward the driver with the fingers of the driver's left hand grabbingthe adjustment lever 27, the adjustment lever 27 is pivotable toward thedriver (two-dotted line in FIG. 3) from an adjustment lever referenceposition (see solid line in FIG. 3). The adjustment lever 27 is appliedwith a biasing force for returning the adjustment lever 27 to theadjustment lever reference position. When the driver takes off theadjustment lever 27 in a state in which the adjustment lever 27 ispulled toward the driver, the adjustment lever 27 returns to theadjustment lever reference position. In the present embodiment, theadjustment lever 27 serves as an adjustment member by which the driverinputs an adjustment command to adjust the output torque of the electricmotor 18 and the electric power generated in the electric motor 18 aswill be described later.

The adjustment lever 27 is provided with a position sensor 28. Theposition sensor 28 outputs an adjustment command corresponding to aposition (operation amount) with respect to the adjustment leverreference position. The position sensor 28 is coupled to the controller16, and inputs the adjustment command to the controller 16. Thecontroller 16 executes a torque adjustment process and a regenerativebraking force adjustment process as will be described later, in responseto the input adjustment command, to adjust the output torque and theregenerative braking force of the electric motor 18.

The handle 5 is further provided with a main switch 29. The main switch29 is, for example, a push button switch and is a switch used to input acommand which causes electric power supply to the electronic componentsin the electric motorcycle 1 to be started or finished. The main switch29 is not limited to the push button switch, and may be a rotary switchsuch as a key cylinder configured such that a key is inserted androtated, or a switch which is able to provide a starting command byholding over an IC card, a portable terminal which enables radiocommunication, etc. The main switch 29 is provided with a main switchsensor 30. The main switch sensor 30 is able to detect whether or notthe main switch 29 has been operated. The main switch 29 is coupled tothe controller 16 and provides a result of detection to the controller16.

As shown in FIG. 2, the electric motorcycle 1 includes a foot brakelever 31. The foot brake lever 31 is provided at a right side of a lowerend portion of the pivot frame 10. The foot brake lever 31 allows apastern of a right foot to be put thereon, and a toe of the right footto be put on its tip end portion. The foot brake lever 31 is pivotabledownward from a foot brake reference position (position in FIG. 1) bydepressing the tip end portion of the brake lever 31 with the toe. Thefoot brake lever 31 is applied with a biasing force for returning thedepressed foot brake lever 31 to the foot brake reference position.

The foot brake lever 31 is an operation member for activating a rearwheel brake mechanism (not shown) provided for the rear wheel 3. Bydepressing the tip end portion of the foot brake lever 31, the rearwheel brake mechanism is activated to apply a mechanical braking forceto the rear wheel 3. By adjusting a displacement amount of the footbrake lever 31, the braking force applied to the rear wheel 3 can beadjusted. The foot brake lever 31 having such a function is providedwith a foot brake sensor 32. The foot brake sensor 32 is a switchingsensor and detects whether or not the foot brake lever 31 has beenoperated. The foot brake sensor 32 is coupled to the controller 16 andprovides a result of detection to the controller 16.

The operation members and sensors arranged in locations construct thecontrol system 33 together with the controller 16, the electric motor18, the electric storage device 20 and the inverter device 21. Inaddition to the above stated sensors, the control system 33 includes avehicle speed sensor 34 for detecting a speed of the electric motorcycle1. The vehicle speed sensor 34 provides a signal corresponding to thedetected speed to the controller 16.

The controller 16 thus configured is configured to adjust the outputtorque and the regenerative braking force of the electric motor 18, asdescribed above. Hereinafter, an operation (adjustment process) of thecontroller 16 in a case where the adjustment command is input byoperating the adjustment lever will be described with reference to theflowchart of FIG. 4. Receiving the adjustment command from the positionsensor 28, the controller 16 initiates the adjustment process, and theprocess goes to step s1. In step s1 which is a torque adjustmentcondition determination step, the controller 16 determines whether ornot a predetermined torque adjustment condition or a predeterminedregenerative braking force adjustment condition is satisfied. The torqueadjustment condition is such that the accelerator grip 5 a has beenangularly displaced from the grip reference position, i.e., theaccelerator grip 5 a has been operated. The regenerative braking forceadjustment condition is, for example, such that the accelerator grip 5 ahas been returned with an operation amount within a predetermined range(e.g., not less than 0 degrees and not greater than 5 degrees) from thegrip reference position, i.e., the accelerator grip 5 a is not operated.The regenerative braking force adjustment condition may be such that arevolutionof the electric motor 18 is equal to or less than apredetermined value, a driving speed is equal to or lower than apredetermined speed, or the brake operation member has been operated.

In step s1, if it is determined that the torque adjustment condition hasbeen satisfied based on the information from the accelerator grip sensor24, the process goes to step s2. In step s2, the controller 16 adjuststhe output torque adjustment (i.e., torque adjustment process) of theelectric motor 18 in response to the adjustment command. If it isdetermined that the regenerative braking force adjustment condition issatisfied based on the output of the accelerator grip sensor 24, theprocess goes to step s3. In step s3, the controller 16 adjusts theelectric power (regenerative braking force) generated in the electricmotor 18 (regenerative braking force adjustment process) in response tothe adjustment command.

Receiving the adjustment command, the controller 16 determines which ofthe torque adjustment condition and the regenerative braking forceadjustment condition is satisfied based on the output from theaccelerator grip sensor 24, and performs different processing based aresult of the determination. When the processing finishes, the processgoes to step s4, and the controller 16 detects whether or not theoperation of the adjustment lever 27 has finished (i.e., the adjustmentlever 27 has been returned to the adjustment lever reference position)based on the adjustment command from the position sensor 28. If it isdetermined that the operation of the adjustment lever 27 has notfinished, the process returns to step s1, whereas if it is determinedthat the operation of the adjustment lever 27 has finished, thecontroller 16 finishes the processing. Hereinafter, the torqueadjustment process in step s2 and the regenerative braking forceadjustment process in step s3 will be described.

Initially, the torque adjustment process performed in response to theadjustment command will be specifically described with reference to thegraph in FIGS. 5A-C. FIG. 5A indicates the operation amount of thethrottle grip 5 a. FIG. 5B indicates the operation amount of theadjustment lever 27. FIG. 5C is a graph showing torque generated in theelectric motor 18 when the operation of FIG. 5A and the operation ofFIG. 5B are performed. In the graphs, horizontal axes indicate time, andvertical axes indicate the operation amount, the operation amount andthe torque, respectively. In the torque adjustment process, thecontroller 16 provides the electric power corresponding to theacceleration command from the accelerator grip sensor 24 to the electricmotor 18 to generate the torque. When the adjustment lever 27 is pulledtoward the driver from the adjustment lever reference position in astate in which the accelerator grip 5 a is operated, the controller 16decreases the output torque of the electric motor 18 in response to theadjustment command.

Specifically, when the adjustment lever 27 is operated in a state inwhich the accelerator grip 5 a is rotated toward the driver toaccelerate the electric motorcycle 1, the inverter driving section 22controls driving of the inverter device 21 to decrease the electricpower supplied to the electric motor 18. The inverter driving section 22decreases the electric power according to a position (i.e., operationamount) of the adjustment lever 27 with respect to the adjustment leverreference position, and is able to decrease the electric powersteplessly from 0% (adjustment lever reference position) to 100%(cut-off position) in a range from the adjustment lever referenceposition to a cut-off position which is beyond a predetermined cut-offoperation amount P1, for example. Instead of steplessly, the inverterdriving section 22 may adjust the generated electric power in responseto the adjustment command from the position sensor 28. When theadjustment lever 27 is moved to the cut-off position, the controller 16electrically disconnects the electric motor 18 and the electric storagedevice 20 via the inverter device 21, and halts the electric powersupply to the electric motor 18 and the power generation in the electricmotor 18. In this state, when the accelerator grip 5 a is returned tothe grip reference position, the controller 16 increases the outputtorque of the electric motor 18 with a ratio corresponding to theadjustment command again.

In the electric motorcycle 1 configured as described above, fineadjustment of the output torque, which is difficult to realize byoperating only the accelerator grip 5 a, can be performed easily byusing the adjustment lever 27. By moving the accelerator grip 5 a towardthe driver, the output torque can be increased, while by returning theaccelerator grip 5 a to the non-operated state, the output torque can belessened. By comparison, by moving the adjustment lever 27 toward thecut-off position, the output torque can be lessened, while by returningthe adjustment lever 27 to the adjustment lever reference position, theoutput torque can be restored. In this way, the output torque can belessened, by operating any of the two operation members 5 a and 27.Since the two operation members 5 a and 27 are moved in oppositedirections to increase and decrease the output torque, the operationbecomes more flexible. In addition, by moving the adjustment lever 27 tothe cut-off position, the operation of the accelerator grip 5 a isnullified and the electric power supply to the electric motor 18 ishalted.

Since the accelerator grip 5 a is rotated to increase or decrease theoutput torque, its operation amount (rotational angle) can be easilykept constant, which makes it easier to drive the electric motorcycle 1at a constant speed. By comparison, since the adjustment lever 27 ispulled or taken off to decrease or increase the output torque, it can beoperated to a great degree in a short time and the output torque can bechanged quickly to a great degree. This makes it possible to perform theoperation for changing the output torque according to a situation.

In the present embodiment, the adjustment lever 27 is an operationmember for decreasing the output torque generated according to theoperation amount of the accelerator grip 5 a, and the controller 16causes the adjustment lever 27 to prevent torque which is equal to orgreater than the output torque corresponding to the operation amount ofthe accelerator grip 5 a from being generated. When the controller 16detects that the adjustment lever 27 is in the cut-off position, basedon the adjustment command from the position sensor 28, the electricmotor 18 and the electric storage device 20 are disconnected in responseto the adjustment command with a priority, irrespective of the operationamount of the accelerator grip 5 a.

Although in the present embodiment, the controller 16 adjusts theelectric power supply to the electric motor 18 such that a rate of theoutput torque of the electric motor 18 is decreased in response to theadjustment command from the position sensor 28, it may adjust theelectric power supply to cause the electric motor 18 to generate torquehaving a torque value (T_(TH)−T_(R)) which is derived by subtracting atorque value T_(R) corresponding to the adjustment command from a torquevalue T_(TH) generated in response to the acceleration command from theaccelerator grip sensor 24.

The rate of the output torque decreasing per unit operation amount ofthe lever, or an amount of the subtraction may be changed, based ondriving states such as the revolutions of the electric motor 18, adriving speed, and a reduction gear ratio (in a case where the powertransmission mechanism 19 includes a transmission). For example, amagnitude of the output torque decreasing per unit operation amount ofthe adjustment lever 27 may be increased or reduced in each of ahigh-speed range, a medium-speed range, and a low-speed range. Or, theoutput torque to be decreased may be changed in response to a change inthe operation amount which occurs with time. Or, a delay characteristicmay be provided to prevent the output torque from rapidly decreasing orrapidly increasing in response to a rapid operation of the adjustmentlever 27. By adjusting the change in the output torque in response tothe adjustment command, the torque can be adjusted according to thedriver's preference.

Next, the regenerative braking force adjustment process performed inresponse to the adjustment command will be specifically described withreference to the graphs of FIGS. 6A and 6B. FIG. 6A indicates theoperation amount of the adjustment lever 27. FIG. 6B is a graphindicating the electric power generated in the electric motor 18 inresponse to the operation shown in FIG. 6A. In the graphs, horizontalaxes indicate time, while vertical axes indicate the operation amountand the generated electric power.

In the regenerative braking force adjustment process, a rotational powerof the rear wheel 3 rotating is transmitted to the electric motor 18 viathe power transmission mechanism 19. In this case, the inverter device21 is activated to cause the electric motor 18 to generate electricpower. The generated electric power is stored in the electric storagedevice 20 via the inverter device 21 and regenerated. During suchregeneration, the power generation in the electric motor 18 becomes arotation resistance to the rear wheel 3, and a braking force is appliedto the rear wheel 3. Hereinafter, this braking force will be referred toas a regenerative braking force to be differentiated from a mechanicalbraking force generated in a brake mechanism.

The controller 16 adjusts the electric power generated in the electricmotor 18 according to the operation amount of the adjustment lever 27,i.e., in response to the adjustment command from the position sensor 28,during the regeneration. The controller 16 decreases the electric powergenerated in the electric motor 18 by pulling the adjustment lever 27toward the driver from the adjustment lever reference position, andincreases the electric power generated in the electric motor 18 byreturning the adjustment lever 27 to the adjustment lever referenceposition.

Specifically, when the adjustment lever 27 is operated during aregenerative state in which the regenerative braking force is applied tothe rear wheel 3 (i.e., during regeneration) (see FIG. 6A), the inverterdriving section 22 controls driving of the inverter device 21 todecrease the electric power generated in the electric motor 18 (see FIG.6B). In this case, the inverter driving section 22 adjusts the electricpower generated in the electric motor 18 according to the position ofthe adjustment lever 27 with respect to the adjustment lever referenceposition, i.e., in response to the acceleration/deceleration commandfrom the position sensor 28. For example, the inverter driving section22 controls driving of the inverter device 21 steplessly such that theelectric power is adjusted from 100% (adjustment lever referenceposition) to 0% (cut-off position), for example, in a range from theadjustment lever reference position to the cut-off position. Instead ofsteplessly, the inverter driving section 22 may adjust the generatedelectric power stepwisely in response to the adjustment command from theposition sensor 28.

As described above, in the electric motorcycle 1, the mechanical brakingforce generated by the rear wheel brake mechanism and the regenerativebraking force applied to the rear wheel 3 can be independently adjustedwith right and left hands, respectively, and the driver can adjust thebraking force to be used and its magnitude according to the situation.Since the accelerator grip 5 a and the adjustment lever 27 are providedseparately, the accelerative force and the regenerative braking forcecan be adjusted independently, and the driver can adjust theaccelerative force and the regenerative braking force according to thesituation.

Since the adjustment lever 27 is provided in the vicinity of the leftgrip 5 b, the driver can easily operate the adjustment lever 27 to inputthe command in the middle of driving. Since the adjustment lever 27serves as an electric cut-off switch between the electric motor 18 andthe electric storage device, another switch need not be provided, whichcan reduce the number of components. By placing the adjustment lever 27in the cut-off position, it becomes possible to attain the cut-off statein which the output torque of the electric motor 18 and the electricpower generated in the electric motor 18 become zero. Therefore, in thestate in which the adjustment lever 27 is placed in the cut-offposition, it is possible to prevent the torque or the regenerativebraking force from being generated even when the accelerator grip 5 a isreturned to the non-operated state and then is operated. This canrelieve a shock which would otherwise be generated when switchingbetween the torque adjustment state and the regenerative braking forceadjustment state occurs.

Since the magnitude of the regenerative braking force can be adjustedaccording to the operation amount of the adjustment lever 27, theregenerative braking force can be adjusted according to the drivingstate or the driver's feeling, as in the brake lever 25. In addition,the regenerative braking force can be adjusted easily by moving theadjustment lever 27 in a forward and rearward direction.

The generated electric power decreasing per unit operation amount of thelever can be changed based on driving states such as the revolutions ofthe electric motor 18, the driving speed, and the reduction gear ratio.This makes it possible to adjust a regeneration amount according to thedriver's preference. In the present embodiment, a rate with which thegenerated electric power is decreased by operating the adjustment lever27 may be changed based on driving states such as the revolutions of theelectric motor 18, the driving speed, and the reduction gear ratio (in acase where the power transmission mechanism 19 includes thetransmission). For example, in a high-speed range, the rate with whichthe generated electric power is decreased when the adjustment lever 27is placed in the adjustment lever reference position may be set about30% to prevent a regenerative braking force of a great magnitude frombeing generated in the high-speed range. On the other hand, in alow-speed range, the generated electric power may be generated with arate of about 100% when the adjustment lever 27 is placed in theadjustment lever reference position to generate a regenerative brakingforce of a great magnitude in the low-speed range.

The rate with which the generated electric power is decreased inresponse to the operation amount of the adjustment lever 27 may bechanged according to each speed range or each speed so that aregenerative braking force generated when the speed of the electricmotorcycle 1 is decreased in a state in which the operation amount ofthe adjustment lever 27 is maintained. In a speed range which is equalto or lower than a predetermined speed, the rate with which thegenerated electric power is decreased in response to the operationamount of the adjustment lever 27, can be reduced. This makes itpossible to suppress the regenerative braking force from workingexcessively in the speed range which is equal to or lower than thepredetermined speed.

Or, a delay characteristic may be provided with respect to the operationof the adjustment lever 27 to prevent the regenerative braking forcecorresponding to the operation of the adjustment lever 27 from rapidlydecreasing or rapidly increasing. By adjusting the change in theregenerative braking force in response to the adjustment command, thetorque can be adjusted according to the driver's preference.

As described above, the controller 16 adjusts an acceleration amount ofthe rear wheel 3 using the operation member different from theaccelerator grip 5 a during the operation of the accelerator grip 5 a,and adjusts the electric power generated in the electric motor 18 duringthe non-operation of the accelerator grip 5 a. The electric motorcycle 1which is capable of adjusting the output torque and the regenerativebraking force by using the adjustment lever 27, is configured not toactivate the electric motor 18 and not to start the electric motorcycle1 unless a starting sequence which is a predetermined starting order issatisfied. Hereinafter, the starting sequence will be described withreference to FIG. 7.

When the driver turns ON the main switch 29, the controller 16 initiatesthe starting process, and the process goes to step s11. In step s11which is a system error check step, the controller 16 checks whether ornot errors have occurred in the sections in the controller 16, theelectronic components connected to the sections etc. If it is determinedthat some errors have occurred in the electronic components, etc., theprocess goes to step s12. In step s12 which is an error warning step,the controller 16 displays information indicating that the errors haveoccurred, on the measurement instrument (not shown) such as a meter, topresent a warning to the driver, and finishes the starting process step.On the other hand, if the determiner section 23 determines that thereare no errors in the system, the process goes to step s13.

In step s13 which is a first condition satisfaction determination step,the determiner section 23 determines whether or not a first startingpermission condition is satisfied. The first starting permissioncondition is such that the brake lever 25 which is a first operationmember has been operated, i.e., the brake lever 25 has been pulledtoward the driver. The determiner section 23 repeats the determinationuntil the first starting permission condition is satisfied based on aresult of detection from the brake sensor 26. If the determiner section23 determines that the first starting permission condition is satisfied,the process goes to step s14.

In step s14 which is a second condition satisfaction determination step,the determiner section 23 determines whether or not a second startingpermission condition is satisfied. The second starting permissioncondition is such that the adjustment 27 which is a second operationmember different from the first operation member has been operated andpulled to the cut-off position. The determiner section 23 repeats thedetermination until the second starting permission condition issatisfied based on the adjustment command from the position sensor 28.If the determiner section 23 determines that the second startingpermission condition is satisfied and a starting condition as will bedescribed later is satisfied, the electric motorcycle 1 is placed in astarting stand-by-state in which the electric motorcycle 1 can bestarted, and the process goes to step s15.

In step s15 which is a count determination step, the determiner section23 determines whether or not a count added in step s16 (described later)exceeds a predetermined value X. If the determiner section 23 determinesthat the count is equal to or less than the predetermined value X, theprocess goes to step s16. In step s16 which is a count adding step, thedeterminer section 23 adds 1 to a count. The count is a value stored inthe determiner section 23 and indicates a duration of a stand-by stateas will be described later. The count is added with one by one at everypredetermined time. After the determiner section 23 adds 1 to the count,the process goes to step s17.

In step s17 which is a starting condition satisfaction determinationstep, the determiner section 23 determines whether or not the startingcondition is satisfied. The starting condition is such that theadjustment lever 27 is placed in a non-cut-off operation state and theaccelerator grip 5 a has been operated. In other words, the startingcondition is such that the adjustment lever 27 is not in the cut-offposition and the accelerator grip 5 a has been rotated from the gripreference position toward the driver. The determiner section 23determines whether or not the starting condition is satisfied based on aresult of detection from the position sensor 28 and the accelerationcommand from the accelerator grip sensor 24. If the determiner section23 determines that the starting condition is satisfied, the process goesto step s18.

In step s18 which is a starting step, the inverter driving section 22drives the inverter device 21, and supplies to the electric motor 18 theelectric power corresponding to the acceleration command from theaccelerator grip sensor 24 and the adjustment command from the positionsensor 28. Thereby, the electric motor 18 is activated to drive the rearwheel 3, and the electric motorcycle 1 starts. After the electricmotorcycle 1 starts in this way, the process goes to step s19. When theelectric motorcycle 1 stops, the process goes to step s20.

In step s20 which is a main switch determination step, the determinersection 23 determines whether or not the main switch 29 has been turnedOFF. When the main switch 29 has been turned OFF, and a command forcausing the electric power supply to the major electronic components ofthe electric motorcycle 1 to be finished, is provided to the controller16, the determiner section 23 determines that the main switch 29 hasbeen turned OFF and finishes the starting process. On the other hand, ifthe determiner section 23 determines that the main switch 29 has notbeen turned OFF, the process goes to step s17.

As described above, in the electric motorcycle 1, the driver canrecognize that the electric motorcycle 1 cannot be started even when theaccelerator grip 5 a is operated in the state in which the adjustmentlever 27 has been moved to the cut-off position. On the other hand, thedriver recognizes that the electric vehicle is in a state in which itcan be started now when the accelerator grip 5 a is operated after theadjustment lever 27 has been returned to the adjustment lever referenceposition. Thus, the driver can recognize that the electric motorcycle 1can be started by a method other than visual check. Therefore, thedriver need not visually check the measurement instrument, etc., atstarting of the electric motorcycle 1, which improves convenience.

If the determiner section 23 determines that the starting condition isnot satisfied in step s17, the process returns to step s15. If thedeterminer section 23 determines that the count is not less than thepredetermined value X in step s15, the process goes to step s21. In steps21 which is a stand-by state determination step, the determiner section23 determines whether or not to continue the starting stand-by statebased on the position of the adjustment lever 27. The determiner section23 detects the position of the adjustment lever 27 based on theadjustment command from the position sensor 28. If the determinersection 23 determines that the adjustment lever 27 is placed in aposition other than the cut-off position, the determiner section 23repeats the determination until it determines that the adjustment lever27 is placed in the cut-off position.

If the determiner section 23 determines that the adjustment lever 27 isplaced in the cut-off position, it determines that the starting stand-bystate should not be continued, and the process goes to step s22. In steps22 which is a count reset step, the determiner section 23 resets thecount to zero. After the resetting, the process goes to step s17.

As should be appreciated from above, in the starting stand-by state,when the adjustment lever 27 is operated at least one or more timesbefore the count reaches X after the first and second startingpermission conditions are satisfied, the starting stand-by state ismaintained. When the starting condition is satisfied in the state inwhich the starting stand-by state is maintained, the electric motorcycle1 can be started. The starting stand-by state can be continued by asimple operation which is the operation of the adjustment lever 27. Thedriver can recognize that the starting stand-by state is continued bysuch a simple operation. In addition, since the starting stand-by stateis continued, the electric motorcycle 1 can be started immediatelywithout satisfying the first and second starting permission conditionsagain. Thus, the operation for starting the electric motorcycle 1 issimple.

By moving the adjustment lever 27 to the cut-off position once after thecount has reached X and the starting stand-by state has been finished,the electric motorcycle 1 can be started. Because of this, the electricmotorcycle 1 can be started by the simple operation after the startingstand-by state has been finished, which improves convenience. Since theoperation member used to input commands for causing the startingstand-by state to be finished and continued is the adjustment lever 27,the driver's intention to cause the electric motorcycle 1 to be kept ina stopped state or to start the electric motorcycle 1 is clearly shownas compared to a case where the operation member is the brake lever 25.In addition, the activated state of the electric motorcycle 1 can beadapted to the driver's intention.

Through step s13 and step s14, the electric motorcycle 1 can be started.After the starting, the torque and the regenerative braking forceapplied to the rear wheel 3 can be adjusted as described above byoperating the accelerator grip 5 a and the adjustment lever 27. Forexample, a case where the adjustment lever 27 is returned to theadjustment lever reference position, then the accelerator grip 5 a isoperated, and then the starting condition is satisfied, will bedescribed. In this case, the controller 16 supplies the electric powercorresponding to the acceleration command from the accelerator gripsensor 24 to the electric motor 18, to increase the output torque.

Although in the present embodiment, the first starting permissioncondition is such that the brake lever 25 has been operated, the presentinvention is not limited to this, but the first starting permissioncondition may be such that the driver is seated on the seat 14. Thestate in which the driver is seated on the seat 14 can be detected byproviding, for example, a seat sensor which transmits informationindicating that the driver is seated on the seat 14 to the controller16, upon the driver being seated on the seat 14. Although in step s14,the second starting permission condition is such that the adjustmentlever 27 has been operated, the present invention is not limited tothis. For example, the second starting permission condition may be suchthat the foot brake lever 31 has been operated (the foot brake lever 31is depressed from the foot brake reference position), or a button switch(not shown) has been operated. For example, the button switch isprovided at the right grip 5 a side of the handle and is constituted bya press button, a rocker switch, etc. After it is determined that themain switch 29 has not been turned OFF in step s20, the determinersection 23 may determine again whether or not the main switch 29 hasbeen operated without returning to step s17.

Next, a case where the electric motorcycle 1 is started in a state inwhich the accelerator grip 5 a has been operated will be described withreference to FIGS. 8A-C and 9A-C. FIGS. 8A-C and 9A-C each graphicallyrepresent a change in the output torque of the electric motor 18 inresponse to the operation of the accelerator grip 5 a and the operationof the adjustment lever 27. FIG. 8A and FIG. 9A each graphicallyrepresent a change in the operation amount of the accelerator grip 5 awhich occurs with time (vertical axis indicates the operation time andhorizontal axis indicates time). FIG. 8B and FIG. 9B each graphicallyshow a change in the operation amount of the adjustment lever 27(vertical axis indicates operation amount and horizontal axis indicatestime). FIGS. 8C and 9C each graphically show a change in the outputtorque of the electric motor 18 which occurs with time in a case wherethe above operations are performed (vertical axis indicates outputtorque and the horizontal axis indicates time).

As shown in FIGS. 8A and 8B, in a case where the adjustment lever 27 isgradually returned from the cut-off position to the adjustment leverreference position, in a state in which the accelerator grip 5 a hasbeen operated, the controller 16 increases the electric power suppliedto the electric motor 18 according to an amount of the operation forreturning the adjustment lever 27 to the adjustment lever referenceposition. Thus, the torque generated in the electric motor 18 increasesaccording to the operation amount of the adjustment lever 27 (FIG. 8C).At a time point when the adjustment lever 27 has been returned to theadjustment lever reference position, prescribed electric powercorresponding to the acceleration command from the accelerator gripsensor 24 is supplied to the electric motor 18, which generates theoutput torque corresponding to the operation amount of the acceleratorgrip 5 a.

On the other hand, as shown in FIGS. 9A and 9B, in a case where theadjustment lever 27 is rapidly returned from the cut-off position to theadjustment lever reference position, in a state in which the acceleratorgrip 5 a has been operated, the controller 16 increases the electricpower supplied to the electric motor 18 according to the accelerationcommand. In this case, in order to return the electric power supplied tothe electric motor 18 to the prescribed electric power corresponding tothe operation amount of the accelerator grip 5 a, the controller 16slowly increases the electric power supplied to the electric motor 18 bygradually increasing the rate with which the electric power supplied tothe electric motor 18 is increased, without rapidly increasing theelectric power with a rate corresponding to the operation amount of theadjustment lever 27 (see FIG. 9C). This makes it possible to prevent theelectric motorcycle 1 from being accelerated abruptly just after thestarting condition is satisfied. By comparison, an increasing rate ofthe electric power supplied to the electric motor 18 is higher than achange rate of the acceleration command of the accelerator grip 5 a.When the electric power supplied to the electric motor 18 reaches theprescribed electric power, it is increased or decreased thereafteraccording to the operation amount of the accelerator grip 5 a and theoperation amount of the adjustment lever 27.

In another case, the front wheel 2 can be braked by operating the brakelever 25 in a state in which the adjustment lever 27 has been returnedfrom the cut-off position to the adjustment lever reference position,and the accelerator grip 5 a has been operated. In this case, theelectric power corresponding to the operation amount of the acceleratorgrip 5 a is supplied to the electric motor 18, and torque of theelectric motor 18 corresponding to the electric power supply is appliedto the rear wheel 3. Thereby, by returning the brake lever 25, theelectric motorcycle 1 can be accelerated rapidly.

In a case where the adjustment lever 27 is moved toward the cut-offposition and then quickly returned toward the adjustment lever referenceposition in the middle of driving, the controller 16 supplies to theelectric motor 18 electric power which is equal to or greater than theprescribed electric power corresponding to the operation amount of theaccelerator grip 5 a. The operation in this case will be described withreference to FIG. 10A-C. FIG. 10A shows a change in the accelerator grip5 a which occurs with time, and FIG. 10B shows a change in the operationamount of the adjustment lever 27 which occurs with time. FIG. 10 Cshows a change in the output torque of the electric motor 18 whichoccurs with time in a case where the above operations are performed. InFIGS. 10A to 10C, the vertical axes indicate the operation amount, theoperation amount and the output torque, and the horizontal axisindicates time.

As shown in FIGS. 10A and 10B, in the middle of acceleration performedby operating the accelerator grip 5 a, the adjustment lever 27 isoperated to decrease the output torque (time t11). Then, the adjustmentlever 27 is returned from that operation position (time t12) to whichthe adjustment lever 27 has been operated, to the adjustment leverreference position (time t13). In this case, if an operation amountΔStroke per unit time is equal to or less than the predetermined value x(ΔStroke≦x), i.e., a time (t13−t12) which passes until the adjustmentlever 27 is returned from the operation position to the adjustment leverreference position is equal to or less than a predetermined time (e.g.,0.1 second to 1 second), the controller 16 supplies to the electricmotor 18 instantaneous electric power (e.g., electric power which istwice or three times as much as the electric power corresponding to theoperation amount of the accelerator grip 5 a) which is greater than theelectric power corresponding to the operation amount of the acceleratorgrip 5 a for a predetermined time after the adjustment lever 27 isreturned to the adjustment lever reference position. Thus, the torque ofthe rear wheel 3 is increased rapidly to prevent reduction of the torquewhich is caused by operating the adjustment lever 27. This can be usedin a case where torque with a great magnitude is necessary for a momentafter the output torque is reduced, for example, in a case where theelectric motorcycle 1 is riding up on a sloping road. Note that a valueof the operation amount becomes zero when the adjustment lever 27 isplaced in the adjustment lever reference position, and its positivevalue increases by pulling the adjustment lever 27 toward the driver.Although in the present embodiment, the instantaneous electric power isprovided according to the operation amount ΔStroke per unit time, it maybe provided when the time (t13−t12) which passes until the adjustmentlever 27 is returned from the operation position to the adjustment leverreference position is equal to or less than the predetermined time.

Embodiment 2

An electric motorcycle 1A according to Embodiment 2 of the presentinvention is similar in configuration to the electric motorcycle 1 ofEmbodiment 1. Hereinafter, regarding the electric motorcycle 1A ofEmbodiment 2, differences from the electric motorcycle 1 of Embodiment 1will be described. The same applies to an electric motorcycle 1B ofEmbodiment 3 and an electric motorcycle 1C of Embodiment 4.

As shown in FIG. 11, the electric motorcycle 1A includes a handle 5Aextending linearly in the rightward and leftward direction. The handle5A is provided with an adjustment lever 27A in a location closer to thedriver than the left grip 5 a. The driver's left hand thumb can contactthe adjustment lever 27A. The adjustment lever 27A can be pushed forwardwith the thumb to be pivoted forward (see two-dotted line in FIG. 11)relative to the adjustment lever reference position (see solid line inFIG. 11). The adjustment lever 27A is applied with a biasing force forreturning the adjustment lever 27A to the adjustment lever referenceposition. When the driver takes off the thumb from the adjustment lever27A after the driver has pushed the adjustment lever 27A, the adjustmentlever 27A returns to the adjustment lever reference position. Theadjustment lever 27A configured as described above has a functionsimilar to that of the adjustment lever 27 of Embodiment 1 except forits location and operation direction. A controller 16A is configured toadjust an acceleration amount and a regenerative braking forcesteplessly according to the position with respect to the adjustmentlever reference position.

The electric motorcycle 1A of Embodiment 2 has advantages as those ofthe electric motorcycle 1 of Embodiment 1.

Embodiment 3

In the electric motorcycle 1B of Embodiment 3, the inverter drivingsection 22 in a controller 16B controls driving of the inverter device21 to increase the electric power generated in the electric motor 18when the operation amount of the adjustment lever 27 is increased in astate in which the accelerator grip 5 a is placed in the grip referenceposition (see FIG. 1). The electric power generated in the electricmotor 18 can be adjusted steplessly in a range of 0% to 100% by movingthe adjustment lever 27 from the adjustment lever reference position(cut-off position) in which the generated electric power is 0% to apredetermined position in which the generated electric power is 100%.

On the other hand, the inverter driving section 22 in the controller 16Bcontrols driving of the inverter device 21 to increase the electricpower supplied to the electric motor 18 when the operation amount of theadjustment lever 27 is increased in a state in which the acceleratorgrip 5 a has been operated (see FIG. 1). The electric power supplied tothe electric motor 18 can be adjusted steplessly in a range of 0% to100% by moving the adjustment lever 27 from the adjustment leverreference position (cut-off position) in which the supplied electricpower is 0% to a predetermined position in which the supplied electricpower is 100%.

Thus, by moving the adjustment lever 27 toward the driver like theaccelerator grip 5 a, the acceleration amount can be adjusted. Thus, itsoperation is easy. Although the electric motorcycle 1B of Embodiment 3is configured in such a manner that the supplied electric power and thegenerated electric power become 0% when the adjustment lever 27 isplaced in the adjustment lever reference position and become 100% whenthe adjustment lever 27 is placed in the predetermined position, theconfiguration may be different. For example, the supplied electric powermay be 0% and the generated electric power may be 100% when theadjustment lever 27 is placed in the adjustment lever referenceposition, and the supplied electric power may be 100% and the generatedelectric power may be 0% when the adjustment lever 27 is placed in thepredetermined position, or vice versa.

The electric motorcycle 1B of Embodiment 3 has advantages as those ofthe electric motorcycle 1 of Embodiment 1.

Embodiment 4

As shown in FIG. 12, the electric motorcycle 1C of Embodiment 4 isprovided with a foot lever 41. The foot lever 41 is provided at a leftside (i.e., at an opposite side of the foot brake lever 31) of a lowerend portion of the pivot frame 10. The foot lever 41 allows a pastern ofa left foot to be put thereon, and a toe of the left foot to be put onits tip end portion. The foot lever 41 is pivotable downward from a footlever reference position by depressing the tip end portion of the footlever 41 with the toe. The foot lever 41 is applied with a biasing forcefor returning the foot lever 41 to the foot lever reference position.When the toe is taken off from the tip end portion of the foot lever 41,the foot lever 41 returns to the foot brake reference position. Inaddition, the foot lever 41 is provided with a foot sensor 42. The footsensor 42 is a switching sensor and is configured to detect whether ornot the foot lever 41 has been operated. The foot sensor 42 is coupledto the controller 16C and provides a result of detection to thecontroller 16C.

A determiner section 23C of the controller 16C is configured todetermine that the second starting permission condition is satisfiedwhen the foot lever 41 has been operated in step s14 which is thestarting process and the foot sensor 42 provides information indicatingdetection of the operation. By operating the foot lever 41 in this way,the starting sequence ends.

Alternatively, the foot lever 41 may be used as an activated stateswitch member. That is, when the foot lever 41 is operated, thecontroller 16C does not activate the electric motor 18 irrespective ofthe operation of the accelerator grip 5 a, while in a non-operated statein which the foot lever 41 is returned to the foot lever referenceposition, the controller 16C supplies to the electric motor 18 electricpower corresponding to the operation amount of the accelerator grip 5 ato activate the electric motor 18. When the foot lever 41 is in thenon-operated state and the accelerator grip 5 a has been operated instep s17, a determiner section 23C in the controller 16C determines thatthe starting condition is satisfied.

As described above, the operation member capable of switching theactivated state may be provided in addition to the adjustment lever 27,the accelerator grip 5 a and the brake lever 25. Instead of the footlever 41, a similar operation member may be used so long as theoperation member is positioned to enable the driver to operate it.

Although in Embodiment 4, the foot lever 41 is provided, a press buttonsuch as the activated state switch button may be provided. This buttonis configured to be turned ON/OFF. When the button is turned OFF, theelectric motorcycle 1 is switched to the activated state in which theelectric power is supplied to the electric motor 18 and the electricpower is generated in the electric motor 18. On the other hand, when thebutton is turned ON, the electric motorcycle 1 is switched to thecut-off state in which the electric power is inhibited from beingsupplied to the electric motor 18 and the electric power is notgenerated in the electric motor 18. As in Embodiment 4, when this buttonis turned ON, the controller 16C determines that the second startingpermission condition is satisfied.

Other Embodiment

Although in Embodiment 1 to Embodiment 4, the adjustment levers 27 and27A are provided on the left grip 5 a and the brake lever 25 is providedon the right grip 5 b, the positional relationship may be reversed.Although in Embodiment 1 to Embodiment 4, the adjustment levers 27 and27A and the foot lever 41 serve as the activated state switch members,the brake lever 25 and the foot brake lever 31 may be the activatedstate switch members as well. In this case, for example, when theadjustment lever 27 is moved to the cut-off position and the brake lever25 is operated, the controller 16 stops supplying of the electric powerto the electric motor 18, while when at least one of the two operationmembers 27 and 25 is in the non-operated state, the controller 16permits the electric power to be supplied to the electric motor 18.Thus, the operation of the two operation members allows the driver torecognize more obviously that the electric motor 18 is deactivated thanthe operation of one operation member.

Although in the electric motorcycles 1 and 1A to 1C of Embodiment 1 toEmbodiment 4, both of the torque adjustment process and the regenerativebraking force adjustment process are executed by operating theadjustment lever 27, either one of the processes may be executed.Specifically, the following embodiments may be adopted. When theadjustment lever 27 is operated in the state in which the acceleratorgrip 5 a has been operated, the torque adjustment process is executed,while even when the adjustment lever 27 is operated in the state inwhich the accelerator grip 5 a has been operated, the regenerativebraking force adjustment process is not executed. Or, even when theadjustment lever 27 is operated in the state in which the acceleratorgrip 5 a has been operated, the torque adjustment process is notexecuted, while when the adjustment lever 27 is operated in the state inwhich the accelerator grip 5 a has been operated, the regenerativebraking force adjustment process is executed. The adjustment lever 27may only serve as the activated state switch member and may not serve asthe torque adjustment member and the regenerative braking forceadjustment member.

The electric motorcycles 1 and 1A to 1C need not go through the abovestated starting sequence, but may go through a simpler startingsequence, for example, a starting sequence in which the electricmotorcycle 1 can be started when either one of the first and secondstarting permission conditions is satisfied.

Although the amount of electric power supplied to the electric motor andthe regeneration amount are adjusted individually according to asituation, as acceleration/deceleration adjustment during driving,torque control for reducing the braking force may be executed when theoperation amount of the lever is small, regeneration control forincreasing the braking force may be executed when the operation amountof the lever is great, or cut-off control may be executed in a boundarybetween the regeneration control and the torque control. In this case,when the lever is operated, the command input by the throttle grip maybe nullified, and acceleration/deceleration control may be executedpreferentially in response to the command input by the lever.

Although the amount of electric power supplied to the electric motor andthe regeneration amount are adjusted individually according to the state(operation amount of the accelerator grip 5 a), as theacceleration/deceleration adjustment during driving, an accelerationcommand corresponding to the operation amount of the accelerator grip 5a may be nullified, the torque adjustment process which produces smallerdeceleration effect may be executed when the operation amount of theadjustment lever 27 is smaller than a predetermined operation amount,and the regenerative braking force adjustment process which producesgreater deceleration effect may be executed when the operation amount ofthe adjustment lever 27 is greater than the predetermined operationamount. In this case, preferably, cut-off control is executed in aboundary between the torque adjustment process and the regenerativebraking force adjustment process.

Although in the electric motorcycles 1 and 1A to 1C of Embodiment 1 toEmbodiment 4, the rear wheel 3 is driven by one electric motor 18, aplurality of electric motors 18 may be coupled together by a gearmechanism, etc., to drive the rear wheel 3. In this case, the inverterdriving section 22 controls the inverter device 21 such that the numberof electric motors 18 which are activated and generate electric power ischanged according to the operation amount of the adjustment lever 27.Thus, the torque and the generated electric power can be adjustedstepwisely.

Although the electric motor 18 is the three-phase AC motor, it may be aDC motor. In this case, a voltage/current controller is provided insteadof the inverter device 21. The voltage/current controller is able tocontrol a current and voltage supplied to the electric motor 18 andhence adjust the output torque and revolutions of the electric motor 18.

In the electric motorcycles 1 and 1A to 1C of Embodiment 1 to Embodiment4, after it is determined that the second starting permission conditionis satisfied in step s14, the controller 16 may display this informationon a measurement instrument such as the meter device which can bevisually checked by the driver. Or, the controller 16 may display therate with which the electric motorcycle 1 is accelerated/deceleratedaccording to the operation amount of the adjustment lever 27 or 27A on ameasurement instrument such as the meter device which can be visuallychecked by the driver.

Although in Embodiment 1 to Embodiment 4, the control system 33 isapplied to the electric motorcycles 1 and 1A to 1C, it may be applied toan electric four-wheeled vehicle, an electric three-wheeled vehicle,etc., so long it is a vehicle in which the drive wheel is driven by theelectric motor 18. Especially, the control system 33 is suitablyemployed in vehicles having handles gripped by the driver's hands.

REFERENCE CHARACTERS LIST

-   -   1 electric motorcycle    -   3 rear wheel    -   5 handle    -   5 a accelerator grip (right grip)    -   5 b left grip    -   16 controller    -   18 electric motor    -   20 electric storage device    -   21 inverter device    -   22 inverter driving section    -   23 determiner section    -   25 brake lever    -   27 adjustment lever    -   31 foot brake lever    -   33 control system    -   41 foot lever

The invention claimed is:
 1. An acceleration control system in anelectric vehicle comprising: an electric motor for driving a drive wheelby electric power supplied to the electric motor; a controller forsupplying the electric power to the electric motor; an accelerationoperation member operated by a driver to input to the controller acommand for causing the drive wheel to be accelerated; and anacceleration amount adjustment member provided separately from theacceleration operation member and operated by the driver to input to thecontroller a command for adjusting an acceleration amount of the drivewheel; wherein the controller controls an amount of the electric powersupplied to the electric motor in response to the command for causingthe drive wheel to be accelerated, which is received as an input fromthe acceleration operation member and the command for adjusting theacceleration amount of the drive wheel, which is received as an inputfrom the acceleration amount adjustment member.
 2. The accelerationcontrol system in the electric vehicle according to claim 1, wherein thecontroller generates the electric power supplied to the electric motorin response to an operation of the acceleration operation member, andsuppresses the electric power supplied to the electric motor in responseto an operation of the acceleration amount adjustment member.
 3. Anacceleration control system in an electric vehicle, comprising: anelectric motor for driving a drive wheel by electric power supplied tothe electric motor; an acceleration operation member for inputting acommand for causing the drive wheel to be accelerated; a controller forsupplying the electric power to the electric motor in response to thecommand from the acceleration operation member; and an accelerationamount adjustment member provided separately from the accelerationoperation member; wherein the acceleration operation member is movablein a first predetermined direction from a predetermined first referenceposition and is applied with a biasing force in a direction opposite tothe first predetermined direction to return the acceleration operationmember to the first reference position; wherein the acceleration amountadjustment member is movable in a second predetermined direction from apredetermined second reference position and is applied with a biasingforce in a direction opposite to the second predetermined direction toreturn the acceleration amount adjustment member to the second referenceposition; and wherein the controller increases the electric powersupplied to the electric motor as an operation amount of theacceleration operation member with respect to the first referenceposition increases and decreases the electric power supplied to theelectric motor as the acceleration operation member moves closer to thefirst reference position when the acceleration operation member returnsto the first reference position; and wherein the controller decreasesthe electric power supplied to the electric motor as an operation amountof the acceleration amount adjustment member with respect to the secondreference position increases and increases the electric power suppliedto the electric motor as the acceleration amount adjustment member movescloser to the second reference position when the acceleration amountadjustment member returns to the second reference position.
 4. Theacceleration control system in the electric vehicle according to claim3, wherein the controller nullifies the operation of the accelerationoperation member and halts electric power supply to the electric motor,when the acceleration amount adjustment member is moved by apredetermined operation amount or greater in the second predetermineddirection from the second reference position.
 5. The accelerationcontrol system in the electric vehicle according to claim 3, comprising:a steering device including two gripping members which are gripped by adriver's right and left hands, respectively; wherein the accelerationoperation member is provided at one of the gripping members; and whereinthe acceleration amount adjustment member is provided at the othergripping member.
 6. The acceleration control system in the electricvehicle according to claim 5, wherein the acceleration operation memberis an operation member of a throttle grip shape which is attached on theone of the gripping members such that the acceleration operation memberis operated to be rotatable in the first predetermined direction aroundan axis of the acceleration operation member; and wherein theacceleration amount adjustment member is an operation member of a levershape which is operated to be movable in the second predetermineddirection.
 7. The acceleration control system in the electric vehicleaccording to claim 4, wherein the controller supplies to the electricmotor prescribed electric power corresponding to the operation amount ofthe acceleration operation member; wherein when the acceleration amountadjustment member is moved by the predetermined operation amount or moreand the acceleration operation member is operated, before starting ofthe electric vehicle, and then the acceleration amount adjustment memberis returned by a predetermined operation amount or more to activate andstart the electric motor, the controller gradually increases theelectric power supplied to the electric motor to the prescribed electricpower.
 8. The acceleration control system in the electric vehicleaccording to claim 3, wherein when a predetermined torque increasingcondition is satisfied after the acceleration amount adjustment memberhas been moved in the second predetermined direction, the controllersupplies to the electric motor instantaneous electric power which isgreater than prescribed electric power corresponding to an operationamount of the acceleration operation member at a time point when thepredetermined torque increasing condition is satisfied.
 9. Anacceleration control system in an electric vehicle comprising: anelectric motor for driving a drive wheel by electric power supplied tothe electric motor; a steering device including two gripping memberswhich are gripped by a driver's right and left hands, respectively; anacceleration operation member which is a grip operation member attachedto one of the two gripping members; an acceleration operation membersensor which detects an operation amount of the acceleration operationmember and outputs an acceleration command corresponding to the detectedoperation amount of the acceleration operation member; an accelerationamount adjustment member which is a lever operation member attached tothe other of the two gripping members; an acceleration amount adjustmentmember sensor which detects an operation amount of the accelerationamount adjustment member and outputs an adjustment command correspondingto the detected operation amount of the acceleration amount adjustmentmember; and a controller which adjusts the electric power supplied tothe electric motor in response to the acceleration command received fromthe acceleration operation member sensor and the adjustment commandreceived from the acceleration amount adjustment member sensor.
 10. Theacceleration control system in the electric vehicle according to claim1, comprising: a steering device including two gripping members whichare gripped by a driver's right and left hands, respectively; whereinthe acceleration operation member is attached to one of the two grippingmembers; and wherein the acceleration amount adjustment member isattached to the other of the two gripping members.
 11. The accelerationcontrol system in the electric vehicle according to claim 10, whereinthe acceleration operation member steplessly or stepwisely outputs thecommand for causing the drive wheel to be accelerated, according to theoperation amount of the acceleration operation member; wherein theacceleration amount adjustment member steplessly or stepwisely outputsthe command for adjusting the acceleration amount of the drive wheel,according to the operation amount of the acceleration amount adjustmentmember; and wherein the controller supplies to the electric motor theelectric power corresponding to the command for causing the drive wheelto be accelerated, when the acceleration operation member is operated,and decreases the supplied electric power at a rate corresponding to thecommand for adjusting the acceleration amount of the drive wheel, whenthe acceleration amount adjustment member is operated.
 12. Theacceleration control system in the electric vehicle according to claim1, wherein the acceleration operation member steplessly or stepwiselyoutputs the command for causing the drive wheel to be accelerated,according to the operation amount of the acceleration operation member;wherein the acceleration amount adjustment member steplessly orstepwisely outputs the command for adjusting the acceleration amount ofthe drive wheel according to the operation amount adjustment member; andwherein the controller supplies to the electric motor the electric powercorresponding to the command for causing the drive wheel to beaccelerated, and decreases the supplied electric power at a ratecorresponding to the command for adjusting the acceleration amount ofthe drive wheel.
 13. The acceleration control system in the electricvehicle according to claim 1, comprising: a steering device includingtwo gripping members which are gripped by a driver's right and lefthands, respectively; and a brake operation member for activating a brakemechanism for mechanically braking the drive wheel; wherein the brakeoperation member is attached to one of the two gripping members, and theacceleration amount adjustment member is attached to the other of thetwo gripping members.
 14. The acceleration control system in theelectric vehicle according to claim 1, wherein the controller changes achange amount of the electric power supplied to the electric motor,corresponding to a unit operation amount of the acceleration amountadjustment member, based on a driving state or a change in theadjustment command which occurs with time.
 15. The acceleration controlsystem in the electric vehicle according to claim 1, wherein when thecontroller determines that the acceleration amount adjustment member hasbeen operated with a predetermined operation amount or more, based onthe adjustment command, the controller causes the electric vehicle tostart.